<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>留言板</title>
    <style>
        .container {
            width: 350px;
            height: 300px;
            margin: 0 auto;
            /* border: 1px black solid; */
            text-align: center;
        }

        .grey {
            color: grey;
        }

        .container .row {
            width: 350px;
            height: 40px;

            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .container .row input {
            width: 260px;
            height: 30px;
        }

        #submit {
            width: 350px;
            height: 40px;
            background-color: orange;
            color: white;
            border: none;
            margin: 10px;
            border-radius: 5px;
            font-size: 20px;
        }
    </style>
</head>

<body>
    <div class="container">
        <h1>留言板</h1>
        <p class="grey">输入后点击提交, 会将信息显示下方空白处</p>
        <div class="row">
            <span>谁:</span> <input type="text" name="" id="from">
        </div>
        <div class="row">
            <span>对谁:</span> <input type="text" name="" id="to">
        </div>
        <div class="row">
            <span>说什么:</span> <input type="text" name="" id="say">
        </div>
        <input type="button" value="提交" id="submit" onclick="submit()">
        <!-- <div>A 对 B 说: hello</div> -->
    </div>

    <script src="js/jquery.min.js"></script>
    <script>
 
        $.ajax({
            type:"get",
            url:"/message/getList",
            success:function(results){
                if(results!=null&&results.length>0){
                    //如果是json类型,前端可以直接将他作为对象进行使用;其余的要转换为对象之后才能进行使用
                    for(var result of results){
                        var divE = "<div>"+result.from +"对" + result.to + "说:" + result.message+"</div>";
                        $(".container").append(divE);
                    }
                }
            }
        });
        function submit(){
             //1. 获取留言的内容
             var from = $('#from').val();
             var to = $('#to').val();
             var say = $('#say').val();
             if (from== '' || to == '' || say == '') {
                 return;
             }
             //调用接口,发到后端
             $.ajax({
                type:"post",
                url:"/message/setMessage",
                contentType:"application/json",
                data:JSON.stringify({
                    "from":from,
                    "to":to,
                    "message":say
                }),
                success:function(result){
                    if(result){
                        //成功
                        //2. 构造节点
                        var divE = "<div>"+from +"对" + to + "说:" + say+"</div>";
                        //3. 把节点添加到页面上    
                        $(".container").append(divE);

                        //4. 清空输入框的值
                        $('#from').val("");
                        $('#to').val("");
                        $('#say').val("");
                    }else{
                        //失败
                        alert("发送失败")
                    }
                }
             });
             
            
         }
        
    </script>
</body>

</html>